JPH0566523U - Oil level warning circuit for vehicles - Google Patents

Abstract

(57) [Summary] [Purpose] To accurately detect the oil level of the engine,
The purpose is to provide an oil level warning circuit for a vehicle that warns the driver in the event of a shortage. [Structure] The oil level warning circuit includes an oil level detection circuit 7, a holding circuit 8, a warning circuit 9, and the like. The oil level detection circuit 7 has an oil level switch 4 as a sensor and an ignition switch 1
Detects the oil level between when 0 is turned on and when the engine is started. Further, the holding circuit 8 receives the output of the oil level detection circuit 7 and receives the output of the ignition switch 1
The output is held until a predetermined time after 0 is turned off, that is, about 60 seconds later. Also, the warning circuit 9 issues a warning based on the output of the holding circuit 8 when the oil level is below a specified value.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil level warning circuit for a vehicle, and more specifically, detects an oil level between the time when the ignition switch is turned on and the time when the engine is started, and warns if there is an abnormality. Related to level warning circuit.

[0002]

[Prior Art]

 Conventionally, generally, to measure the engine oil level of a vehicle, a rod-shaped oil level gauge that is standardly attached to the vehicle is inserted into the oil tank when the engine is stopped, and a scale marked on the tip of the gauge is used. This is done by reading the oil that has adhered to the part, and the oil level is measured by this to determine the suitability. Although this method can accurately determine the oil level, it requires the engine room to be opened and operated, and it is not often performed due to the annoyance.

Therefore, a warning device as shown in FIG. 5 may be used. This device measures the oil level while the engine is rotating. The float 2 with the magnet 3 embedded in it is floated on the surface of the oil 1, and the reed switch 4 is used to move the float 2 above and below the oil 1 surface. When it is detected, the lamp 5 gives a warning when the oil 1 surface falls below the specified value. In this case, the delay circuit 6 is provided to prevent the lamp 5 from being erroneously lit due to a temporary fluctuation of the oil level due to running of the vehicle.

[0004]

[Problems to be solved by the device]

 However, because the oil is supplied to each engine while the engine is rotating, the oil level drops and does not match the oil level when the engine is stopped, that is, it does not match the value measured by the level gauge described above. There was also a problem that the oil level fluctuates depending on the operating conditions of the engine, so it was not always possible to detect an accurate amount.

An object of the present invention is to provide an oil level warning circuit for a vehicle, which accurately detects an oil level of an engine and warns a driver when the oil level is insufficient.

[0006]

[Means for Solving the Problems]

 The vehicle oil level warning circuit according to the present invention is a vehicle oil level warning circuit that warns when the oil level falls below a specified value based on an on / off signal of an oil level switch arranged in an oil tank. The oil level detection circuit that detects the oil level between the time when the ignition switch is turned on and the time when the engine is started, and the output of the oil level detection circuit are received at a predetermined time after the ignition switch is turned off. Up to the holding circuit for holding the output, and a warning circuit for warning when the oil level is below a specified value based on the output of the holding circuit.

[0007]

[Action]

 Based on the above configuration, when the ignition switch is turned on, the oil level detection circuit detects the appropriateness of the oil level based on the on / off signal of the oil level switch located in the oil tank until the engine starts. To do. This detection state is held by the holding circuit until a predetermined time after the ignition switch is turned off. If the held state indicates an oil level above the specified value, the warning circuit does not issue a warning, and this state is maintained until a certain time after the ignition switch is turned off. Even if the oil level is lowered by the rotation of the engine and the oil level switch gives a corresponding signal by then, no warning is given. On the other hand, if the held state shows the amount of oil below the specified value, a warning is issued by the warning circuit, and this state continues until the ignition switch is turned off.

[0008]

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an oil level warning circuit for a vehicle according to an embodiment of the present invention. The oil level warning circuit is composed of an oil level detection circuit 7, a holding circuit 8, a warning circuit 9, etc. The oil level detection circuit 7 has an oil level switch 4 consisting of a reed switch as a sensor and an ignition switch. The oil level is detected after the switch 10 is turned on and before the engine is started. Further, the holding circuit 8 receives the output of the oil level detection circuit 7 and holds the output for a predetermined time after the ignition switch 10 is turned off, that is, for about 60 seconds in the present embodiment. Further, the warning circuit 9 issues a warning based on the output of the holding circuit 8 when the oil level is below a specified value. It should be noted that power is supplied to these circuits from the battery 11 via the ignition switch 10.

FIG. 2 shows an electric circuit embodying a block diagram of the vehicle oil level warning circuit shown in FIG. The operation of this circuit when oil is filled will be described with reference to FIG. 3. First, the reed switch is used as the oil level switch 4 as shown in FIG. 5, and it turns on when oil is filled. ing . Then, when the ignition switch 10 is turned on, the oil level switch 4 is turned on, so that the transistor Q ₁ is turned off, so that the base potential of the transistor Q ₂ rises and is turned on.

[0011] The transistor Q ₂ is turned ON, the transistor Q ₄ also turned ON because the base potential drops of the transistor Q ₄ which is connected via a resistor R ₃ to the collector of the transistor Q _2, through this end resistor R ₄ It will be charged the capacitor C ₁ Te, Trang register Q ₃ turns oN about 0.1 seconds in the present embodiment up the base potential of the transistor Q _3. Regarding the transistor Q ₅ , when the ignition switch 10 is turned on, the base potential tends to rise due to the time constant of the resistor R ₆ and the capacitor C ₂ , but since the transistor Q ₂ is turned on, the base at that time is turned on. It turns off because the potential drops. Therefore, the warning lamp 5, which is the load of the transistor Q ₅ , does not light.

After the ignition switch 10 is turned on, when the engine is started to rotate, the oil in the oil tank is supplied to each engine, and therefore decreases. At this time, it is assumed that the oil level switch 4 is turned off. When the oil level switch 4 is off, the transistor Q ₁ is on and the transistor Q ₂ is off. However, since the transistor Q ₃ is ON, the base potential of the transistor Q ₅ is low, and therefore the transistor Q ₅ remains OFF and the warning lamp 5 does not light.

Next, when the ignition switch 10 is turned off, the electric charge of the capacitor C ₁ is discharged via the resistor R ₅ and the transistor Q ₃ . In this embodiment, the time constants of the capacitor C ₁ and the resistor R ₅ are set so that the transistor Q ₃ remains in the ON state for about 60 seconds. The 60 seconds is taken into consideration that it takes about 60 seconds for the oil supplied to each engine to return to the oil tank after the ignition switch 10 is turned off.

Therefore, when the ignition switch 10 is turned on again within 60 seconds after the ignition switch 10 is turned off, not all the oil has returned to the tank yet, so the oil level switch 4 is turned off. have, the transistors Q ₁ is turned ON, the transistor Q ₂ turned OFF. However, transistor capacitor Q ₃ are transistors Q ₄ to that retain the ON state capacitor C ₁ is charged through the turned ON resistance R _4. Therefore, the base potential of the transistor Q ₅ which is connected to the collector of the transistor Q ₃ via the diode D ₃ and the like is low, the transistor Q ₅ is not a warning is issued because never turned ON. That is, the measurement is not performed before the oil returns.

On the other hand, the operation of this circuit when oil is insufficient will be described with reference to FIG. First, when the ignition switch 10 is turned on, the oil level switch 4 is turned off, so that the transistor Q ₁ is turned on and the transistor Q ₂ is turned off. Therefore, the transistor Q ₄ is turned off and the capacitor C ₁ is not charged, so the transistor Q ₃ is also turned off. Therefore, the capacitor C ₂ connected to the base of the transistor Q ₅ is charged through the resistor R _6, and after 0.2 seconds, the time constant is determined as described above in this embodiment, but the transistor Q ₅ is When it is turned on, the warning lamp 5 lights up to warn. However, since the capacitor C ₁ is in the discharged state, if the ignition switch 10 is once turned off and then turned on again, the oil level is detected again.

[0016]

[Effect of the device]

 As described above, according to the present invention, it is possible to know the stable oil level when the engine is stopped without being affected by the operating conditions of the engine, in the same accurate condition as when measuring with the rod-shaped oil level gauge. .

[Brief description of drawings]

FIG. 1 is a block diagram of an oil level warning circuit for a vehicle according to an embodiment of the present invention.

FIG. 2 is an electric circuit diagram embodying the block diagram shown in FIG.

FIG. 3 is a timing chart of each part when oil is filled.

FIG. 4 is a timing chart of each part when oil is insufficient.

FIG. 5 is a diagram showing the principle of a conventional oil level warning device for a vehicle.

FIG. 6 is a diagram showing changes in the oil level in the oil tank during rotation and stop of the engine.

[Explanation of symbols]

 4 Oil level switch (reed switch) 5 Warning lamp 7 Oil level detection circuit 8 Holding circuit 9 Warning circuit 10 Ignition switch

Claims (1)

[Scope of utility model registration request] 1. An oil level warning circuit for a vehicle, which warns when an oil level falls below a specified value based on an on / off signal of an oil level switch arranged in an oil tank, in which an ignition switch is turned on. An oil level detection circuit that detects an oil level between the start of the engine and the start of the engine; a holding circuit that receives the output of the oil level detection circuit and holds the output until a predetermined time after the ignition switch is turned off; An oil level warning circuit for a vehicle, comprising: a warning circuit that warns when the oil level is below a specified value based on the output of the holding circuit.